Extrajunctional resting Ca2+ influx is not increased in a severely dystrophic expiratory muscle (triangularis sterni) of the mdx mouse

Neurobiology of Disease

Rebecca Ashmore¹  Judy E Anderson¹  Anton Gueorguiev¹  Jacquelyne S Chu²  Diana M Roshek²  C.George Carlson² 

[1] Department of Human Anatomy and Cell Science, University of Manitoba, 730 William Ave., Winnipeg, Manitoba R3E OW3, Canada;Department of Physiology, Kirksville College of Osteopathic Medicine, Kirksville, MO 63501, USA;

关键词: Duchenne muscular dystrophy;    mdx mouse;    Dystrophinopathies;    Calcium;    Calcium channels;    Muscle necrosis;   

DOI  :  

来源: DOAJ

【 摘 要 】

Freshly isolated adult mdx and nondystrophic (C57B110SnJ) muscle fibers were used to examine the potential role of resting Ca2+ influx in the pathogenesis of Duchenne and related dystrophies. Microfluorimetric determinations of resting divalent cation influx were obtained from undissociated intact muscle fibers in the triangularis sterni (TS), a thin expiratory muscle. Morphological evidence indicated severe dystrophic alterations in the mdx TS at 5 months, and a prononunced loss of fibers with connective tissue infiltration in older animals. To examine resting Ca2+ influx, fibers were loaded with FURA PE3 and the rate of quenching of intracellular signal following the extracellular addition of Mn2+ was determined from extrajunctional regions. There was no significant difference in quench rate between nondystrophic and mdx TS fibers. These results indicate that severe dystrophic pathology in the absence of dystrophin is not due to generalized increases in resting Ca2+ influx.

【 授权许可】

Unknown